Strip mill with roll cartridge



Se t. 8, 1964 -r. SENDZIMIR STRIP MILL. WITH ROLL CARTRIDGE 6Sheets-Sheet l INVENTOR. TADEUSZ Ssuoz mm WWW/99w ATTORNEYS Filed June26 1962 Sept. 8, 1964 Filed June 26, 1962 STRIP T. SENDZIMIR 3,147,648

MILL. WITH ROLL CARTRIDGE 6 Sheets-Sheet 2 INVENTOR.

TADEUSZ Sauozmm,

ATTORNEYS Sept. 8,' 1964 T. SENDZIMIR 3,147,643

STRIP MILL WITH ROLL CARTRIDGE Filed June 26, 1962 6 Sheets-Sheet 3INVENTOR. TADEUSZ SENDZIMIR,

ATTORNEYS Sept. 8, 1964 T. SENDZIMIR STRIP MILL WITH ROLL CARTRIDGE 6Sheets-Sheet 4 Filed June 26, 1962 INVENTOR. TADEUSZ Scuozmm,

ATTORNEYS Sept. 8, 1964 Filed June 26, 1962 T. SENDZIMIR 3,147,648

STRIP MILL WITH ROLL CARTRIDGE 6 Sheets-Sheet 5 FIG 8 INVENTOR. TADEUSZSerwz mm,

7 #144 62? WM, WM)? ATTORNEYS Se t. 8, 1964 T. SENDZIMIR 3,147,648

STRIP MILL WITH ROLL CARTRIDGE Filed June 26, 1962 6 Sheets-Sheet 6INVENTOR. TAoEusz SENDZ mm,

ATTORNEYS United States Patent 3,147,648 STRIP MILL WITH ROLL CARTRIDGETadeusz Sendzimir, T. Sendzimir, Ina, R0. Box 1350, Waterbury, Conn.Filed June 26, 1962, Ser. No. 205,372 23 Claims. (Cl. 8tl38) Theinvention relates to rolling mills for metal and other strip material,and more particularly to improvements on mills characterized by the useof very thin work rolls which are supported substantially along theirwhole length by intermediate rolls. The intermediate rolls are supportedin turn by freely rotating casters alternating on their shafts withfixed supports mounted in a very rigid mill housing. Such a mill isdisclosed in applicants United States Patent No. 2,776,586.

The rigid construction of mills of this type enables metal strips to berolled with great accuracy. The effective use of very small rolls makesit possible to reduce even relatively hard materials down to very lightgauges. Such mills also permit change in the crown or profile of themill thereby controlling the flatness of the strip produced. It has beenfound, however, that in mills of this type the work rolls, backingrolls, and other precision parts, as well as the guides and sprayingmeans for coolant lubricant are exposed to severe damage upon theoccurrence of a cobble, that is, when a strip, instead of passingthrough the mill, flat and under tension, passes instead in a folded-upstate. There are several causes of cobbling, such as failure of theelectric controls which causes a suddent loss of tension exerted by theunwinding or winding reels, an edge crack in the strip that causes it tofold, or local overheating due to some defect on the surface of thestrip that causes a sudden heavy waviness in that portion of the strip,and consequent loss of tension. When cobbling occurs, a folded strip ofat least three thicknesses passes through a portion of the roll bite.This increases locally the roll separating forces to the extent that therolls and backing elements often cannot withstand the increased pressurewithout damage, such as spalling and breaking. In addition to this, theunaffected portion of the strip continues to be fed into the mill byinertia of the corresponding parts, causing it to accordion. As aresult, when the mill finally comes to a halt there is an accumulationof strip material under extreme pressure within the mill, causing damageto the rolls, strip guides and lubricant sprays. Thus, there is ablocking of the rolls in the mill and the rolls must be removed. This isaccomplished only with great difficulty and loss of valuable productiontime.

Leaving aside the problem of cobbling, the usual periodic'servicing andcleaning of mills of this type require several hours. Each roll must beremoved, and the supporting casters have to be released and taken outshaft by shaft. Then they must be individually replaced by newlyserviced and verified shafts which must be inserted and locked inposition one by one, followed by the insertion of the rolls and theguides.

It is an object of the present invention to provide a mill of the typeindicated with a novel means and method for mounting the working rollsand the supporting elements therefor in such a way that they may bequickly and easily removed as a self-contained and independent unit.

Previous efiorts in this direction have not been fully satisfactory.They have taken the form of providing, instead of a plurality ofindividual supports or saddles for each caster carrying shaft, onecommon cradle for the bottom part of the mill and one for the top part.This makes the removal of the casters for servicing considerice axialsupport of the rolls, since suitable thrust bearings and/ or plates aremounted on this door. Also, the connection with the screwdown actuatingmechanism which changes the angular position of the eccentric shaftscarrying the casters, is aflixed to the housing and has to be separatelydisconnected. See US. Patent 2,766,586, FIG URE 3, and US. Patent2,479,974.

The control of crown or profile of the mill mentioned above, theprinciple of which is disclosed in U.S. Patent 2,194,212, FIGURES 7, 8,16 and 17, and described on page 4, lines 12 and following comprisessecondary eccentrics which may even be incorporated in the saddles; buttheir actuating mechanisms pass through the mill housing and have theirmotors and indicators on top of the hous: ing. These have to beindividually disconnected, wheneven such saddles and other bearingelements are re moved, again involving a great loss of production time.

Consequently it is an object of the present invention to provide a millof the type indicated wherein the working rolls and all of the pressurebearing elements are comprised in a self-contained and independent unit,including all of the necessary operating and control elements such asscrewdown mechanisms and the like, which units may be easily inserted orremoved from the mill housing.

It is an object of the present invention to provide a rolling millwherein the working rolls and the pressure bearing elements may bequickly and easily removed, requiring only the disconnection of thedrive spindles and lubricant and oil pressure hose fittings. 1

It is a further object of the invention to provide a mill of the typedescribed wherein the removable unit may be replaced by a similar unitor by a unit of difierentwork and support roll arrangement, thus greatlysimplifying mill change-over.

It is a further object of the present invention to provide a mill of thetype described with a novel spaced support for the guides and sprayholders which will not be subject to warping, crushing or bending by theexcessive pressure of accumulated strip in the case of cobbling.

These and other objects of the invention which will bedescribedhereinafter or will be apparent to one skilled in the art uponreading these specifications, are accomplished by that construction andarrangement of parts of which exemplary embodiments will now bedescribed. Reference is made to the accompanying drawings wherein:

FIGURE 1 is a perspective view of the lower half of a mill cartridgewith the rolls and casters removed.

FIGURE 2 is a side elevation of the mill housing with the cartridge inplace.

FIGURE 3 is a sectional view taken along the section line A-A of FIGURE2.

FIGURE 4 is a partial cross-sectional view of the work rolls andsupporting rolls taken along the line BB of FIGURE 3.

FIGURE 5 is a perspective view of a lower drawer member showing thecoolant jets.

ably easier, but does not help in case of a cobble. Be-

sides the structure still requires a hinged front door, for

FIGURE 6 is a partial cross-sectional view of the spring means forraising the lower cradle prior to removal of the cartridge.

FIGURE 7 is a side elevation of the mill with a cartridge in place. Partof the figure is in section to show a two-high roll arrangement.

FIGURE 8 is a cross-sectional view taken along the line CC of FIGURE 7.

FIGURE 9 is a partial sectional view taken along the line DD of FIGURE 3showing the independent crown control means.

FIGURE 10 is a partial sectional view taken along the line E-E of FIGURE9.

Referring to FIGURES 2 and 3, the mill of the present invention isprovided with a rigid housing generally indicated at 1. It has a bore 3extending through it from side to side, and front and rear openings 3aand 3b for the entrance and exit of the material being rolled. Thehousing is generally like that of the mill of the patent first mentionedabove, and may have elastic deflection characteristics heretofore knownin such housings. The single bore 3 extending axially through the centerof the housing receives a cartridge generally indicated at 4, formounting the work rolls and support mechanisms therefor. The cartridgeis made up of two halves or cradles indicated at 2 and 2.

The lower cradle 2' is illustrated in FIGURE 1. The

cradles 2 and 2 may be identical, but only the lower cradle 2' need beprovided with the slots 60 and openings 38 which will be more fullydescribed hereinafter. As will be noted from FIGURE 1, the cradle 2 isin the form of a hollow half-cylinder shell 4 with a plurality of spacedribs 5 perpendicular to its axis. The elements 2 and 2' with the ribsare preferably but not necessarily formed as an integral casting.Certain surfaces will be machined as hereinafter pointed out. The spacedribs 5 have a plurality of perforations 7, the axes of which areparallel to the axis of the cradle, corresponding perforations in theseveral ribs being coaxial. The perforations 7 house the doubleeccentric bearings as shown at 81 and 70 in FIGURE 9. These are thebearings for the caster supporting shafts 82, later described. Thenumber of such backing shafts will determine the number of groups ofcoaxial holes in the ribs, the cradle illustrated in FIG- URE 1 havingin each rib four such groups for four such bearings. Each rib is alsoprovided with a cut-away portion indicated at 7 to accommodate theworking rolls and first and second intermediate backing rolls. Thecradles, being held apart at their corners, are configured to havesurfaces 8 which will be separated when the cradles are in assembly, toprovide throats for entrance and exit of the strip. As will be morefully described hereinafter, the cartridge 6 will house the workingrolls, the intermediate backing rolls, the backing bearings, thecasters, lubricant jets and screwdown and crown adjustment means. Whilethe cartridge 6 may be removed from the housing 1 in any suitablemanner, FIGURE 3 illustrates convenient means for such removal. Adjacentthe bore 3, the mill is provided with a short bridge 22. The end of thebridge 22 which extends away from the bore 3 leads to an adjacent cradlecarriage 23 which rides on rails indicated at 23'. A hydraulic ormechanical moving means such as a straight line actuator or' itsequivalent (indicated generally at 21) may be used to shove thecartridge 6 out of the bore 3, across the bridge 22, and onto the cradlecarriage 23 by which the cartridge may be transported to the maintenanceshop for necessary overhaul or repair. Similarly, the same or differentcartridge may be brought into position by means of the cradle carriageand immediately inserted into the bore 3 by means of the same straightline actuator 21.

It is important in a mill of the type described that the cartridgeassume a proper bearing against the walls of the bore in the millhousing. 1. Means are therefore provided which tendto move the twocradles away from each other and press them firmly against the bore 3 inthe housing. While any suitable positive jacking means maybe used forthis purpose, FIGURES 2 and 7 illustrate the cradle 2 as being providedwith screw jacks 50 at each of its corners. When the cartridge 6 isproperly inserted into the bore 3, the jacks are actuated to separatethe cradles 2 and 2' thereby assuring adequate bearings of the cradlesagainst the bore, while at the same time locking the cartridge withinthe housing. It is also within the scope of the present invention toprovide pins 51 at diagonally opposite corners of one of the cradles andcooperating perforations in the other cradle to assure proper alignmentof the cradles with respect to each other. Prior to removal of thecartridge from the housing, the jacks 50 are released.

4 This will lower the cradle 2, disengaging it from the bore 3.

Means may also be provided for raising the cradle 2' to disengage itfrom the bore 3 once the cradle 2 has been lowered. One such means isillustrated in FIGURES 2 and 6 at 52. The cradle 2 is provided withlongitudinal channels or slots 60 of T-shaped cross-section. Referringto FIGURE 6, a bar 53, is located within the channel 68. The bar isprovided with a plurality of recesses 54- extending along its entirelength. Springs or spring discs 55, the total force of which iscalculated to be such as to exceed the weight of the cartridge 6 withall of the rolls, etc., are located within the recesses E4 and are heldin place by means of screws 57 and nuts 56. It will be noted that twosuch lifting means are provided on the cradle 2', one to the right andone to the left of the center of the outside periphery of the cradle.When the cartridge is located and locked in place in the bore 3, the bar53 in each of the lifting means is depressed so as to lie wholly withinthe slot 60, the nuts 56 in each of the lifting means being depressedinto the recesses 54, so that there is a clearance between the face 58of the bar 53 and the surfaces 59 of the slot 6%). In the process ofremoval of the cartridge from the bore 3, when the jacks 50 have beenreleased and the cradle 2 lowered, the lifting means are free to raisethe cradle 2, and the cartridge may be removed as described above.

In the preferred embodiment, the bore 3 as well as the cartridge 6 aremade with a slight longitudinal taper, for example between 25:1 and50:1. When this is done, the housing may be provided with suitableopenings 15 for the injection of oil under high pressure into theinterface between the bore and the cartridge. This tends momentarily toseparate the two surfaces and to create a thin film of oil therebetween.Static friction is reduced, and the linear actuator 21 can easily andsafely push the cartridge out of the housing and onto the carriage 23.

When the bore and cartridge are so tapered, the cartridge can be made inone piece, or in a plurality of pieces but without the jacks 59. This istrue because the taper is so calibrated that the cartridge will fit thebore snugly when pulled into place by the actuator 21, while thefriction is reduced by the above mentioned oil injection. It has beenfound that even when a cobble has occurred which has expanded a singlepiece cartridge or separated a two piece cartridge, the rigid housingmay suffer some elastic distortion of a magnitude of a few thousandthsof an inch. Nevertheless, when oil is injected under pressure throughthe openings 15, the surfaces of the cartridge and the bore will becaused to separate for the formation of the oil film aforesaid,providing such fluid friction conditions that the linear actuator caneject the cartridge for cleaning and repair after the cobbled strip hasbeen cut off or withdrawn. A new cartridge may then be placed in thehousing, with a total interruption of work time of only a few minutes.

Referring to FIGS. 4 and 5, the cartridge of the present invention isprovided with upper and lower drawer-type slides 24 and 24', hereinafterreferred to as drawers. FIGURE 5 shows a perspective view of the lowerdrawer 24'. As will be noted, the drawer comprises an open frame-likestructure with two elongated portions 24a and 24b and end portions 25aand 2519. As shown in FIG- URE 5, the drawer 24' is slidably mounted inthe lower cradle 2 with the outer edges of the portions 24a and 24b ofthe drawer supported by notches 5a in the ribs 5 of the cradle.

As above mentioned, applicants structure presents another surprisingadvantage in the fact that the crossribs 5 of the cradles providejointly a strong support for the drawers 24, 24 housing rolls andcoolant jets 13, 13', FIGURE 4. This is a source of considerable troubleon mills not using this invention where the strip guides which alsocarry the coolant jets are built in the form of bridges across the mill.These bridges (see e.g. 66, FIGURE 4 of US. Patent 2,776,586) arelocated close to the roll bit where there is not enough depth left for aheavy bridge section; and the bridges would be deformed under thepressure of a cobble. On the other hand, mill saddles (see 4, FIGURES 1and of Patent 2,776,586) are excellent for transmission of roll pressurefrom the caster shafts to the housing but, again owing to obvious spacelimitations are not capable of supporting any load applied to the top ofthe thin ring of the saddle, such as is frequently present if anaccordion is formed. Consequently, damage by a cobble includes usuallydeformed bridge guides and coolant jets and sometimes even saddle rings.

In order to better take advantage of the availability of such spacedsupports across the width of the mill, applicant is providingdrawer-type slides 24, 24, FIGURES 4 and 5, one for the lower and onefor the upper half of the mill, which carry thrust faces 25a and 25b forintermediate rolls 10 and 10, similar to those disclosed in copendingapplication Serial No. 756,574, filed August 22, 1958, in the name ofthe present inventor, and now US. Patent 3,076,360.

The end portions 25!) of drawers 24 and 24' are provided with outwardlyextending threaded members 26 and 26'. As illustrated in FIGURE 3, thethreaded member 26' is engaged by an internally threaded sleeve 27 whichin turn is rotatably mounted in a framework 27a mounted on the cartridge6. The internally threaded member 27' is provided with a crank 28' bywhich it may be turned. This structure enables the mill operator tocontrol the axial position of the intermediate support rolls 10', evenduring the operation of the mill, by .axial movement of the drawer 24.The upper drawer 24 is similarly slidably mounted in the upper cradle 2and serves as thrust bearing means for the upper pair of firstintermediate rolls 10. The upper drawer is provided with a threadedmember 26 engaged by an internally threaded sleeve 27 which in turn isprovided with a crank means 28. Thus it will be seen that the upperintermediate rolls of the first series may be separately controlled asto their axial position. Such control of the axial positions .of theintermediate support rolls is necessary to obtain accurate control overthe shape of the strip and especially the edge portions thereof, byaligning the strip edge with certain tapers or reliefs provided on thesaid intermediate rolls as described in the above mentioned copendingapplication or in US. Patent 2,778,586.

The portions 24a and 24b of the drawer 24' are provided withlongitudindal bores 29' which serve as ducts for coolant fluid jetnozzles 13 (see FIGURE 4) located in holes 30. These nozzles aredirected chiefly against the surface of the work roll 9 so as toabstract heat therefrom as Well as from the strip passing above it. Aswill be understood by one skilled in the art, the upper drawer 24 isprovided with similar coolant fluid ducts and nozzles 13,

which nozzles are directed primarily toward the surface of the work roll9.

The cartridge structure of the present application has obviated the needfor a door or end plate on the side of the mill which is faced by theoperator. Instead, a bracket-like bridge element 16 forming an integralor removable part of the cartridge is used. A tubular element 33 isfitted to a central bore in the bridge 16 and carries thethrust bearing32 for the work rolls 9 and 9'. The thrust bearing 34 at the oppositeend of the work rolls 9 and 9' is carried at the end of a plunger 35actuated by a hydraulic cylinder or the equivalent (not shown) andslidably mounted in a centrally located bore in a fixed back plate 36.With this arrangement, upon removal of the tubular bracket 33, theplunger 35 may be caused to moveiforwardly which in turn pushes bothrolls at least part way out through the bridge 16 where they can beeasily extracted by hand.

The more or less open construction of the mill of the presentapplication has a further important advantage. Modern mills of this typeare capable of reductions in the order of 50% even on highlywork-hardening metal strips of, for example, .040 inch by 50 inchsection, and speeds in excess of 3000 f.p.m. Such a mill calls for afiow of coolant liquid at from 500 to 1000 g.p.m. The mill of thepresent application with its open sides makes such flow possible.

In the past, in mills requiring such a heavy flow of "coolant liquid, aproblem was presented in the evacuation of such liquid from the bottomof the mill. The construction of such mills often presented pocketswhere dirt and metal chips had a tendency to accumulate. These pocketsand this accumlation of dirt impeded the flow of the coolant liquid.This has been completely remedied in the mill of the presentapplication. As illustrated in FIGURE 1, the lower cradle 2' is providedat its lowermost point with a plurality of coaxial perforations 38 ineach of the cross ribs 5. Due to the taper of the cradle, the liquidcollected therein will have a tendency to run from right to left as seenin FIGURE 3. A suction connection generally indicated at 39 may beprovided in order to further accelerate evacuation of the spent coolantliquid.

In a mill of this type it is necessary to provide means for regulatingthe distance between the work rolls 9 and 9', and the pressure withwhich they bear upon the work piece. Such control means are usuallyreferred to as screwdown means. The screwdown means used on the mill ofthe present invention is similar to that disclosed in the patents to thesame inventor set forth above. That is to say, screwdown is effected byrotating, i.e., changing the angular position of, one or more of thecaster carrying shafts, which have eccentric portions. In the preferredembodiment, the two upper shafts are so rotated, and, in order toincrease the accuracy of the control and minimize torsional deflectionon wider mills, rotating means are provided at both ends of such shafts.

At will be noted from FIGURE 4, the work rolls 9 and 9 are backed byfirst series intermediate backing rolls It] and 10' which, in turn arebacked by second series intermediate backing rolls 11 and 11. The secondseries intermediate backing rolls are themselves backed by a pluralityof casters 12 and 12' mounted on shafts indicated at 82 and 82' (FIGURES4 and elsewhere). As stated above, the number of caster carrying shaftsis ,not limiting. The exemplary cradle illustrated in FIGURE 1 hasprovision for four such shafts, and FIGURE 2 illustrates four suchshafts 82 in the upper cradle and four similar shafts 82 in the lowercradle. As will be clear from FIGURES 1 and 3, the caster shafts aresupported at intervals throughout their length by the cradle ribs 5,with the casters themselves located between the ribs.

While any suitable means may be used to actuate the screwdown mechanism,since it is an object to provide in this invention a completelyself-contained cartridge, a preferred form of actuating mechanism is ahydraulic rotary actuator, one of which is mounted and keyed on each endof the upper two caster shafts. One type of such actuator is known underthe trade name of Rotac made by the Ex-Cell-O Corporation, of Detroitandes sentially consists of an oil tight housing with a shaft in thecenter and a fixed vane with a sliding seal against said shaft. Anothervane is attached to the shaft and is slidably sealed against the twoinner faces and the outer periphery of said housing. An admission ofhydraulic fluid under pressure on one side of the fixed vane,

while the space on the other side of the said fixed vane is connected todrainage, causes rotation of the shaft up the ends ,of the eccentriccaster-carrying shafts, the actuators are subject to reactionproportional to the hydraulic fluid pressure. Applicant has devised anovel arrangement whereby the reaction torque of two adjacent actuatorscancel each other. As shown most clearly in FIG- URES 2 and 3, suitablegrooves 1 are machined n the outer faces of the actuator housings 17.These grooves are at the top and bottom of the housings and are parallelto each other. A slide member 18 is inserted in the space between theseparallel grooves on two adjacent housing members. This arrangementallows lateral displacement of the housing members 17 with respect toeach other due to the eccentricity of the caster carrying shafts, butwill not permit the housings to rotate about their respective shafts.The use of hydraulic actuating means has the further advantage ofassuring a symmetrical rotation of both eccentric shafts. This isaccomplished by control of the flow of hydraulic fluid, as for example,by the use of Well known flow-splitting valves. Thus the screwdownmechanism is self-contained with the cartridge, and requires onlyconnection to and disconnection from a source of hydraulic pressure andpressure control means when cartridges are changed.

The mill of the present invention is also provided with means forcontrolling the crown, contour or flatness of the work piece. Suchcontrol means are shown in FIG- URES 9 and 10. This adjustment also isaccomplished by means operating on the shafts 82. While such contourcontrol means may be provided on any one or all of such shafts, in thepreferred embodiment the upper two shafts in the upper cradle areprovided with such means. As shown in FIGURE 9, the caster bearingshafts 82 are keyed to eccentrics 81 by which screwdown is attained asdescribed above. Eccentric rings 70 are located in the proper bores 7 inthe ribs of the cradles. The eccentric rings 70 are free to rotatewithin the bores 7. Each eccentric ring 70 is provided with a gearsegment 71 riveted thereto, one on either side of the ring. The gearsegments 71 mesh with a double rack 72 which may form an integral partof a screw 73. The screw 73 is engaged by a nut 74 which is rotatablymounted in the peripheral portion of the upper cradle, but is heldagainst axial movement. The nut 74 carries about its periphery gearteeth 75. A horizontally mounted worm 77 engages the teeth 75. The worm77 is rotatably mounted on a shaft 76. The shaft 76 runs across thewidth of the mill and carries a plurality of worms 77 thereon to actuatethe crown control mechanisms located at each rib. The shaft 76 may beturned in either direction by motor means (not shown but mounted on thecartridge) in control of the mill operator. A magnetic clutch, orequivalent, generally indicated at 78 is keyed to the shaft 76 wherebyworm 77 may be engaged to rotate with the shaft. Rotation of the worms77 will cause movement of the teeth 75, which in turn through .the nut74 will actuate the screw 73 and the double rack 72. In this way, theececntric rings 70 will be rotated thereby changing the relative heightsof the bearing supports for the shaft 82. In this way, the crown of thework piece may be controlled to insure the desired flatness,irrespective of the screwdown.

As described above, FIGURES 1 through 4 show an embodiment with workingrolls, backing rolls and casters in what is known as a l234 cluster.That is, each working roll is backed by two first series intermediaterolls, which in turn are backed by three second series intermediaterolls, which, are in turn backed by four rows of casters I2 and 12 Itwill be understood by one skilled in the art, that cartridges withvarious roll arrangements, such as 1-2, 123 and l2-34, or others may beused. It is one of the advantages of the mill of the present applicationthat one and the same mill may be converted from one roll arrangement toanother by simply inserting cartridges of diiferent design, whichconversion may be accomplished in a matter of minutes. FIGURES 7 and 8illustrated the mill of the present invention with a twohigh cartridge,i.e., a cartridge containing two plain rolls with their chocks. Theinterchangeability of cartridges is of far reaching significance. Forexample, the mill of this invention is particularly suitable for eitherskin-pass rolling or polishing of strip or sheet steels in wide widths.Such steels are often rolled in relatively small production unitsdesigned for a modest production, often sufficient to operate the millonly one shift a day. However, in such production, it is necessary tohave either a twohigh skin-pass or polishing finishing mill in order togive the material the surface texture required after a final annealingand pickling operation. This represents a serious capital outlay whichmay not be remunerative because, while the main reduction mill works oneshift or eight hours a day, the finishing mill can handle the stripsproduced in an eight hour day in less than one hour. Thus, the savingsobtained by the ability to combine both the reducing and finishing millsin one is manifest.

In the two high mill of FIGURES 7 and 8, a cartridge is providedconsisting of an upper cradle 61 and a lower cradle 61. Each cradleconsists of two longitudinal box section beams connected by necks and 90respectively to form one continuous body, and further reinforced bybolted ties 62 and 62. The upper and lower cradles house work rollchocks 63 and 63 and standard rolls 64 and 64' respectively.

These rolls are mounted on bearings 65 and 65' respectively at theirnecks. Upper chocks 63 are connected to piston rods 66 of verticalscrewdown cylinders 67. The cylinders 67 by exerting a suitable downwardpressure provide the necessary screwdown action. The cylinders are alsoused to lift the upper rolls by pulling upwardly on their chocks whenrequired. The lower roll 64 is connected through a universal joint 68 toa drive means not shown. The upper and lower cradles aligned by the pins51 may be expanded against the bore 3 by means of jacks 50 as describedwith respect to FIGURES 1 through 4. Means for inserting and removingthe cartridge may also be identical with those described with respect toFIGURES 1 through 4.

Other elements or appurtenances of rolling mills of this general type,being conventional have not been illustrated, or if illustrated have notbeen described. Among these may be mentioned a motor drive for the mill,a pinion stand, coolant-lubricant circulating and filtering means, alubricant sump or the like. It will be understood that the mill will beconnected to a suitable pinion stand by disengageable drivingconnections, and that in mills of the type in which the first seriesintermediate rolls are mounted in drawers, the drive Will preferably beapplied to one or more of the second series intermediate rolls.

Modifications may be made in the invention without departing from thespirit of it. The invention having been described in certain exemplaryembodiments, what is claimed as new and desired to be secured by LettersPatent is:

1. In a rolling mill structure a housing having a transverse cylindricalbore and front and rear openings for the entrance and exit of a strip tobe rolled, and a cartridge located within said bore, said cartridgebeing made up of at least two parts with semi-cylindrical outersurfaces, and containing rolls and pressure bearing elements therefor,said cartridge being insertable and withdrawable from said bore as aunit, a linearly acting power means connected with said cartridge formoving it within said bore, means for forcing the said parts of saidcartridge away from each other so as to lock said cartridge in saidbore, and means effective within said cartridge and independent of saidforcing means for varying the screwdown of said mill.

2. The structure claimed in claim 1 wherein said cartridge containsbearings for the necks of the rolls of a Z-high mill, said bearingsbeing movable toward and away, from each other within the confines ofsaid cartridge.

3. The structure claimed in claim 1 wherein said cartridge has a bodycharacterized by a plurality of spaced transverse ribs, wherein saidribs have a plurality of axially aligned perforations therein, shaftsextending through and mounted in said perforations, casters located onsaid shafts and lying between said ribs, said rolls comprising a pair ofworking rolls, and at least one set of intermediate rolls locatedbetween said working rolls and said casters.

4. In a rolling mill structure a housing having a transverse bore andfront and rear opening for the entrance and exit of a strip to berolled, and a cartridge located within said bore, and containing rollsand pressure bearing elements therefor, said cartridge being insertableand withdrawable from said bore as a unit, a linearly acting power meansconnected with said cartridge for moving it within said bore,saidcartridge having a body characterized by a plurality of spacedtransverse ribs, said ribs having a plurality of axially alignedperforations therein, shafts extending through and mounted in saidperforations, casters located on said shafts and lying between saidribs, said rolls comprising a pair of working rolls, and at least twosets of intermediate rolls located between said working rolls and saidcasters and forming a first and second series of intermediate rolls,drawer means mounted for transverse sliding movement on said ribs, saiddrawer means having end portions, the intermediate rolls of the firstseries being located within said drawer means and having thrust bearingsagainst said ends, and means on said cartridge. for selectively movingsaid drawer means and for fixing the relative positions thereof.

5. The structure claimed in claim 4 in which the last mentioned meanscomprises a bracket having screw means for adjusting the positions ofsaid drawers, a portion at least of said bracket means being movable andadapted to form a thrust bearing for one end of said working rolls, andmeans for providing a thrust bearing for the other end of said workingrolls, said last mentioned means being a power means capable of movingsaid working rolls in the direction of their axes for removal thereof.

6. The structure claimed in claim 4 wherein at least two adjacent onesof the shafts on which said casters are mounted are provided witheccentric portions for screwdown purposes, and wherein means areprovided on the cartridge for adjusting the angular positions of saidshafts.

7. The structure claimed in claim 4 wherein at least two of the shaftson which said casters are mounted are provided with eccentric portionsfor screwdown purposes, and wherein means are provided on the cartridgefor adjusting the angular positions of said shafts, said last mentionedmeans comprising power means attached to the ends of said shafts, theeccentric portions of said shafts respectively being arranged so thatscrewdown is effected by equal and opposite angular movements of saidshafts, and interconnections between the said power means such that theymay slide with respect to each other in a direction transverse to theaxes of the shafts but cannot rotate with respect to each other.

8. The structure claimed in claim 7 wherein said shafts having bearingmeans within the perforations of said ribs, wherein eccentric collarsare provided between said bearing means and said shafts, and whereinmeans are provided in the cartridge for rotating said eccentric collarswhereby to control the contour of a work piece being rolled.

9. The structure claimed in claim 8 wherein the means for rotating theeccentric collars of each shaft comprise gear teeth on said collars, arack engaging said gear teeth and having a screw threaded portion, nutsengaging the screw threaded portions of the racks and a common shaftmeans mounted in said cartridge and having driving connections with saidnuts, there being with respect to each g 10 such driving connection amagnetic clutch electrically operable from a position outside saidcartridge.

10. The structure claimed in claim 8 in which said drawers havelongitudinally extending elements perforated for the passage ofcoolant-lubricant, said elements having at intervals throughout theirlengths jet means for delivering coolant-lubricant against said workingrolls.

11. In a roll mill structure a housing having a transverse bore andfront and rear openings for the entrance and exit of a strip to berolled, and a cartridge located within said bore and containing rollsand pressure bearing elements therefor, said cartridge being insertableand withdrawable from said bore as a unit, and a linearly acting powermeans connected with said cartridge for moving it within said bore, andwherein said cartridge contains bearings for the necks of the rolls of a2-high mill, said bearings being movable toward and away from each otherwithin the confines of said cartridge by means mounted on said housingand automatically engageable and disengageable with a pair of said rollbearings upon insertion and removal of said cartridge.

12. In a rolling mill structure a housing having a transverse bore andfront and rear openings for the entrance and exit of a strip to berolled, and a cartridge located within said bore and containing rollsand pressure bearing elements therefor, said cartridge being insertableand withdrawable from said bore as a unit, and a linearly acting powermeans connected with said cartridge for moving it within said bore, andin which the body of said cartridge is formed of two parts having meansat both ends for aligning the parts with respect to each other, andmeans also at both ends for urging the parts away from each other.

13. The structure claimed in claim 12 wherein the lowermost of saidparts is provided with means for resiliently urging said part away fromthe interior surface of said bore.

14. In a rolling mill structure a housing having a transversecylindrical bore and front and rear openings for the entrance and exitof a strip to be rolled, and a cartridge located within said bore, saidcartridge being made up of at least two parts with semi-cylindricalouter surfaces, means for forcing the said parts of said cartridge awayfrom each other so as to lock said cartridge in said bore, andcontaining rolls and pressure bearing elements therefor, said cartridgebeing insertable and withdrawable from said bore as a unit, and alinearly acting power means connected with said cartridge for moving itwithin said bore, and wherein said housing is provided with passagewaysintersecting said bore, whereby lubricant can be forced into the spacebetween the outer surface of said cartridge and the inner surface ofsaid bore.

15. A cartridge element for a mill of the class described comprisingopposed body parts, means at the ends of said body parts for maintainingaxial alignment thereof, means at the ends of said body parts for urgingsaid parts away from each other, said body parts each comprising anouter shell and a plurality of ribs in spaced relationship, said ribshaving axially aligned bores, shafts having bearings in said bores,caster members mounted on said shafts in spaced relationship and lyingbetween said ribs, a pair of Working rolls, and at least one series ofintermediate rolls lying between said working rolls and said casters.

16. The structure claimed in claim 15 in which at least two series ofintermediate rolls lie between said working rolls and said casters,drawer means slidably mounted on said ribs, said drawer means containingand forming end thrust bearings for the first series of intermediaterolls.

17. The structure claimed in claim 16 including a bridge attached to thelower part of said cartridge, and means on said bridge for selectivelymoving said drawer means.

18. The structure claimed in claim 17 wherein the said bridge meansforms thrust bearing means for end por- 1 l tions of the intermediaterolls of the second series, certain at least of said rolls having attheir opposite ends means for separable connection to. a power sourcefor driving said mill.

19. The structure claimed in claim 18 wherein certain at least of theshafts on Which said: castersare mounted have eccentric portions. forscrewdown purposes, and means located on said cartridge for adjustingthe. angular positions of said shafts.

20. The structure claimed in claim 19 wherein said last mentioned meansare hydraulic positioning means mounted upon the ends of said shafts,and include means for preventing the rotation of said hydraulicpositioning means With respect to said cartridge.

21. The structure claimed in claim 20 including means in connection withsaid ribs for producing selectively a deflection of said last mentionedshafts for contour control purposes.

22,. The structure claimed in claim 21 wherein the ribs of the lowercartridge part have coaxial perforations adjacent the inner surface ofthe shell for the drainage of coolant-lubricant.

23. In aroll mill structure a housing having a transverse bore and frontand rear openings for the entrance and'exit of a strip to be rolled, anda cartridge located within said bore and containing rolls and pressurehearing elements therefor, said cartridge being insertable andwithdrawable from said bore as a unit, and a linearly acting'power meansconnected with said cartridge, for moving it within said bore, the outersurface of the said cartridge and the surface of said bore havingcorresponding tapers.

References Cited in the file. of this patent UNITED STATES PATENTS749,745 Von Philp Ian. 19, 1904 2,037,210 Guente Apr. 14, 1936 ,479, 74Sendzirnir t al. Aug. 23, 1949

1. IN A ROLLING MILL STRUCTURE A HOUSING HAVING A TRANSVERSE CYLINDRICALBORE AND FRONT AND REAR OPENINGS FOR THE ENTRANCE AND EXIT OF A STRIP TOBE ROLLED, AND A CARTRIDGE LOCATED WITHIN SAID BORE, SAID CARTRIDGEBEING MADE UP OF AT LEAST TWO PARTS WITH SEMI-CYLINDRICAL OUTERSURFACES, AND CONTAINING ROLLS AND PRESSURE BEARING ELEMENTS THEREFOR,SAID CARTRIDGE BEING INSERTABLE AND WITHDRAWABLE FROM SAID BORE AS AUNIT, A LINEARLY ACTING POWER MEANS CONNECTED WITH SAID CARTRIDGE FORMOVING IT WITHIN SAID BORE, MEANS FOR FORCING THE SAID PARTS OF SAIDCARTRIDGE AWAY FROM EACH OTHER SO AS TO LOCK SAID CARTRIDGE IN SAIDBORE, AND MEANS EFFECTIVE WITHIN SAID CARTRIDGE AND INDEPENDENT OF SAIDFORCING MEANS FOR VARYING THE SCREWDOWN OF SAID MILL.